All textures in .JPG file format. There are 1 multimaterials for only models. 1 for bark, 3 for branches, 1 for Twigs, 1 for leafs. 1 for fruit.
It is possible to change the bark if you want without a with lime, use Vgx-Citrus aurantium 00-bark01-diff.jpg

There are 3 Mat librairie, one for Vray 2.0SP5, one for MentalRay and one for Scanline